Lubbock requires a permit before code-regulated work on a building or its systems, and the city's list names structural, electrical, plumbing and mechanical changes, not insulation. That list doesn't settle whether your attic job needs one, so when we aren't sure, we call the city's building office and ask before we start, and when a permit is needed, we get it from the city where your house sits and handle the paperwork. If you'd like to ask yourself, the city's Building Inspection Department lists 806-775-2087 and 806-775-3155 for permit questions.
Texas doesn't license building contractors and remodelers, but Lubbock makes them register with that department, and registering takes proof of a $100,000 general liability policy or a $20,000 compliance bond, so it's a fair thing to ask any installer about. Around Lubbock and in Wolfforth, Slaton, Levelland, Plainview, Littlefield and Brownfield, we see a lot of houses whose attics were insulated once and never topped up, and we do the job the same way wherever the house sits.